swiotlb: Use physical addresses instead of virtual in swiotlb_tbl_sync_single

This change makes it so that the sync functionality also uses physical
addresses.  This helps to further reduce the use of virt_to_phys and
phys_to_virt functions.

In order to clarify things since we now have 2 physical addresses in use
inside of swiotlb_tbl_sync_single I am renaming phys to orig_addr, and
dma_addr to tlb_addr.  This way is should be clear that orig_addr is
contained within io_orig_addr and tlb_addr is an address within the
io_tlb_addr buffer.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 4cedc28..af47e75 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -433,8 +433,7 @@
 
 	/* NOTE: We use dev_addr here, not paddr! */
 	if (is_xen_swiotlb_buffer(dev_addr)) {
-		swiotlb_tbl_sync_single(hwdev, phys_to_virt(paddr), size, dir,
-				       target);
+		swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
 		return;
 	}